Related problem. (https://support.mozilla.org/en-US/questions/1045480)

Hi can you explain in a bit more detail. *How are you discovering this ? Presumably using Task Manger * Are you able to run a functonal Firefox ? > *Ordinarily multiple versions of the Firefox current Release will not run together as firefox.exe <br />Of course it is normal to run multiple Firefox windows. ** It is possible to run multiple instances in some circumstances. ** Often if not deliberate it may be because of a malware problem.<br />Please try scans with multiple and up to date tools <br > Please report back with what you try and the results. * Firefox does take some time to shutdown, and you may sometimes need to allow it five minutes or so. ** After giving Firefox a chance to close down kill all its processes and any plugincontainer. After doing that does Firefox start up ok ? <br />And as a single process. '''Your plugins are multiple and quite possibly part of the issue.''' I will post further about this later if necessary. Meanwhile *'''Temporarily disable every plugin.''' **See [[Disable or remove Add-ons]] ** Does that help ? <br /> Does it prevent the Firefox duplication ? * You have multiple shockwave etc ** You should only have the latest version. <br /> You are best not using the Director one at all. <br /> You may need Adobe's uninstaller utility to sort this out properly. * Realplayer related software has previously caused issues when Flash Player is also installed. ( I wonder if another issue could be appearing ?) ** I haven't a clue yet what the ''RealNetworks(tm) RealDownloader PepperFlashVideoShim Plug-In '' is (I hope it is not stealing Google Chrome's plugin) ---------- MALWARE Sometimes a problem with Firefox may be a result of malware installed on your computer, that you may not be aware of. You can try these free programs to scan for malware, which work with your existing antivirus software: * [http://www.microsoft.com/security/scanner/default.aspx Microsoft Safety Scanner] * [http://www.malwarebytes.org/products/malwarebytes_free/ MalwareBytes' Anti-Malware] * [http://support.kaspersky.com/viruses/disinfection/5350 Anti-Rootkit Utility - TDSSKiller] * [http://general-changelog-team.fr/en/downloads/viewdownload/20-outils-de-xplode/2-adwcleaner AdwCleaner] (for more info, see this [http://www.bleepingcomputer.com/download/adwcleaner/ alternate AdwCleaner download page]) * [http://www.surfright.nl/en/hitmanpro/ Hitman Pro] * [http://www.eset.com/us/online-scanner/ ESET Online Scanner] [http://windows.microsoft.com/MSE Microsoft Security Essentials] is a good permanent antivirus for Windows 7/Vista/XP if you don't already have one. Further information can be found in the [[Troubleshoot Firefox issues caused by malware]] article. Did this fix your problems? Please report back to us!

Your System Details shows; Installed Plug-ins Garmin Communicator Plug-In 4.0.4.0 Garmin Communicator Plug-In 4.2.0.0 BETA Shockwave Flash 12.0 r0 Shockwave Flash 16.0 r0 Having more than one version of a program may cause issues. '''Flash''' Grab the uninstaller from here: '''[http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html Uninstall Flash Player | Windows]''' '''[http://helpx.adobe.com/flash-player/kb/uninstall-flash-player-mac-os.html Uninstall Flash Player | Mac]''' Then reinstall the latest version. Flash Player '''v16.0.0.296<br>https://www.adobe.com/products/flashplayer/distribution3.html''' Shockwave Director '''v12.1.6.156 http://get.adobe.com/shockwave/'''